Armature mounting means for electromagnetic relays



P. A. HANOLD ARMATURE MOUNTING MEANS FOR ELECTROMAGNETIC RELAYS Filed Nov. 9, 1961 I I FIG-4 um \,,1

FIGS

FIG. I-

FIG? FIG-8 INVENTOR PAUL AHANOLD WWW ATTORNEYS United States Patent ()fiiice 3,187,141 ARMATURE MGUNTHNG MEANS FOR ELECTROMAGNETIC RELAYS Paul Alexander Hanold, Fort Branch, Ind, assignor to American Machine & Foundry Co., a corporation of New Jersey Filed Nov. 9, 1961, Ser. No. 151,259 3 Claims. (Cl. 200-87) This invention relates to electromagnetic relays and, more particularly, to relays of the type which employ a restoring spring for moving the armature, upon de-energization of the relay, to and holding it in its normal position.

In the past, relays have been provided which include an electromagnet mounted on the base of an L-shaped field member, the leg of the field member extending parallel to the electromagnet. An armature is pivotally mounted upon the field member for movement relative to the other end of the electromagnet, which has an exposed pole piece, in response to actuation of the relay.

In many types of such relays, the armature is flat and is mounted for pivotal movement about the upper edge of the field member, there being a restoring spring, usually in the form of a helical tension spring, mounted on the side of the field member opposite to the electromagnet, for moving the armature to its normal position upon de-energization of the relay.

It has been found that for many applications, especially those where space requirements are critical, such a relay is unsuitable because the restoring spring and that portion of the armature which extends past the field member on the side adjacent to the restoring spring occupies so much space that other components of the installation cannot be eifectively operated.

Accordingly, one of the objects of the invention is to provide a new and improved electromagnetic relay of the type employing a restoring spring.

Another object of the invention is to provide new and improved means for mounting the armature in a relay of the type including an electromagnet mounted on the base of an L-shaped field'member.

Still another object is to provide an electromagnetic relay of relatively long life and in which an armature is mounted so that it does not frictionally engage any adjacent parts during movement between actuated and unactuated positions.

A further object is to provide new and improved restoring spring means for mounting an armature in an electromagnetic relay.

In order that the, manner in which these and other obejcts are attained in accordance with the invention can be understood in detail, reference is had to the accompanying drawing, which forms a part of this specification, and wherein:

r FIG. 1 is a side elevational view illustrating one embodiment of this invention mounted in a housing, the housing being in section;

FIG. 2 is an end elevational view of the relay illustrated in FIG. 1 looking in the direction of lines 2--Z;

FIG. 3 is a top plan view of the relay illustrated in FIG. 1 looking in the direction of lines 33;

FIG. 4 is a plan view illustrating one embodiment of the restoring spring prior to its being bent and assembled in the relay;

FIG. 5 is a side View illustrating one feature of the restoring spring of FIG. 4;

FIG. 6 is an end elevational view, similar to FIG. 2, of a modification of the relay shown in FIG. 1;

FIG. 7 is a side elevational view of the stop member shown in FIG. 6; and

. 11 by a pair of 3,187,141 Patented June 1, 1965 FIG. 8 is a side elevational view, on an enlarged scale for clarity, of the pressure plate shown in FIG. 6.

Referring now to the drawing, the embodiment of the invention there shown generally includes an electromagnet 19, a field member 11, an armature 12, and switch means indicated generally by reference numeral 13 enclosed in a housing 14'.

Electromagnet 16' is of conventional construction and includes a coil 15 wound on a bobbin 16 and a core 17 which extends coaxially through the bobbin and the coil and has an exposed pole piece 18 engageahle with armature 12. The lower end of core 17 is of reduced diameter and extends through an aperture in the leg or base 1? of field member 11, the field member being L-shaped and of ferromagnetic material. Bobbin 16 is secured, as by an adhesive such as epoxy resin, to core 17 and field member 11. Field member 11 also includes a leg 29 which extends perpendicular to base 19 at one end thereof and parallel to electromagnet 1d. The length of leg 20 is less than that of the electromagnet so that leg 29 terminates at its upper end a distance slightly greater than one-half the length of bobbin 16. Although electromagnet 1%) is illustrated as being of a DC. actuated type, the electromagnet can be provided with means, such as a laminated core and a shading coil, so that it will operate on A.C. energy.

Housing 14 includes a base plate 21, a side wall 22, a top wall 23 and a door 24 connected to and mounted upon top wall 23 by a hinge 25. A support bracket 26 is mounted upon base plate 21 by suitable means such as a plurality of screws 27. Obviously though, other means, such as studs, bolts or sheet metal speed nuts, could be used to secure the bracket and base. Bracket 26 includes a body portion 28 which is spaced from base plate 21 and extends parallel thereto. The lower end of core 17 extends through an aperture in bracket 26 and is deformed, such as by rolling its edges over the bottom surface of the bracket adjacent to the aperture, as indicated at 29, to rigidly connect core 17, field member 11 and bracket 25.

Armature 12 is L-shaped and includes a flat body portion 3% and a leg 31 which extends perpendicular to body portion 3i? and downwardly therefrom. A restoring spring 32 is fixedly secured to le 26 of field member screws 33 and to leg 31 of armature 12 by a pair of rivets 34. It is apparent, though, that the spring can be secured solely by screws, rivets, welding, mechanical deformation such as staking, or by any combination thereof. The restoring spring 32 mounts the armature in a position wherein the lower edge of leg 31 terminates closely adjacent to the upper edge of leg 20, such edges being parallel to each other and sufiiciently close so that the magnetic field induced in field member 11 as a result of energization of electromagnet 1i? readily passes into armature 12 which, of course, is constructed of magnetic material.

Door 24 is pivotal about hinge 25 from the closed position shown in FIG. 1 in a clockwise direction to an open position. When door 24 is closed, it lies immediately adjacent to screws 33 and rivets 34, the door being flat and extending generally parallel to legs Zil and 31. It will be thus apparent that the space to the left of the armature and the field member, as viewed in FIG. 1, is relatively small, such feature being especially advantageous in those situations where, for one reason or another, a component such as door 24 must be positioned closely adjacent to the relay.

Restoring spring 32 is of spring metal material such as a beryllium copper alloy. Where it is desired to provide a magnetic shunt across the gap between the field memher and the armature. the restoring spring can .be of a -:by a ridge 43.

ferromagnetic spring material. restoring spring has a pair of apertures 35 and a pair of apertures 36 through which screws 33 and rivets 34, respectively, extend. The restoring spring is advantageously stamped from a sheet metal blank and is permanently bent so that, when the spring is unassembled, it has a shape similar to that shown in FIG. 5. As illustrated in FIG. 5, the restoring spring has an arcuate medial portion which prevents any unnecessarily high stress concentrations due to a sharp bend, such medial portion being indicated by the area between the ends of bracket A; The end portions, on either side of the medial portion, are flat and contain apertures 35 and 36 to avoid any unnecessary stress concentration in the restoring spring in the vicinity of screws 33 and rivets 34. Apertures 35 could be elongated in a vertical direction so that the gap between the armature and the field member can be adjusted upon loosening and tightening screws 33. The angle of the bend in the restoring spring is sufficiently great so that, when the restoring spring is assembled, the bend is partially straightened to prestress the spring and provide the necessary restoring forces and sufiicient contact pressures for operation of the relay.

The adjacent edges of legs 2% and 31 extend transversely of restoring spring 32 along lines immediately adjacent and parallel to the dotted line in FIG. 4. Restoring spring 32 flexibly mounts armature 12 upon field member 11 for movement relative to electromagnet It the center point of such movement also being located in the vicinity of the dotted line of FIG. 4, i.e., in the vicinity of the transverse medial portion. The upper half of restoring spring 32 is substantially fully engaged with leg 31 and the lower half is substantially fully engaged with leg 20. Although the spring 32 is illustrated as mounted on the outside surfaces of the armature and of the field member, it is to be understood that the spring can be arranged adjacent to the inside surfaces of both the armature and the field member or adjacent to the inside surface of one of and to the outside surface of I the other of the armature and the field member.

As shown in FIG. 4, the

and provide means by which the relay can be connected to suitable circuitry for proper operation. Terminals 381 are arranged in two parallel vertical rows, there being four terminals in each row. Mounted on the ends of the upper two terminals in each row are a pair of vertically spaced fixed contacts 39 and 40. The lowest terminal in each row is connected to a different end of coil 15 whereas the remaining terminal in each row, i.e., the terminal second from the bottom as viewed in PEG. 1,

is connected by means of an insulated conductor 41 to one end of a movable contact arm 42 having a movable contact 43 secured thereto. Each movable cont-act 43 is disposed between each pair of cooperating fixed contacts 39 and 49.

- A support member 44 of molded insulation material is secured to armature 12 by a rivet 45 (FIG. 3), there being a shim 46 of insulation between support member 44- and the upper surface of body portion 36 of armature 12. Rivet 45 is recessed in a cylindrical recess 47 bounded A rivet 49 secures each contact arm 42 to member 44. The upper end of each conductor 41 extends through a cylindrical projection 50 which extends through apertures in body portion 30 and shim 45 and is connected to one of rivets 49. Conductors 4-1 are flexible so that they do not interfere with movement of the armature. I

A stop memberfil of insulation material is integral with base 37 and extends perpendicular thereto between fixed contacts 39 and 4t) and movable contact 43 to prevent arcing between adjacent contacts FIQ, iii and i3. Stop member 51 includes a downwardly facing edge 52 which overlies the upper surface of bobbin l6 and a downwardly facing edge 53 which overlies the upper surface of shim 46 to limit movement of armature 12 upwardly beyond its normal position. In its normal position, i.e., the position occupied when the electromagnet is de-energized, the upper surface of shim 46 is slightly below edge 53.

In operation, when the relay is de-energized, the movable portions of the relay are held in their normal position illustrated in FIG. 1 by restoring spring 32. The restoring spring biases armature 12 away from engagement with pole piece 18, the biasing force of the restoring spring being balanced by the spring forces of contact arms 42, such forces being sufficiently great to effect the necessary contact pressure between each of movable contacts 43 and its associated fixed contact 39. A non-magnetic shim 54 is attached to the under surface of body portion 3t) to prevent the armature from sticking to the pole piece, due to residual magnetism, upon de-energization of the relay. v

When the relay is energized, as by passing current through coil 15, a magnetic field is established, creating forces which attract the armature to the pole piece and cause the armature to move, from the position shown in FIG. 1 to a position wherein body portion 34) abuts pole piece it; and is parallel to base 11. Movement of the armature from its normal position to its actuated position causes contacts 43 to move downwardly from engagement with contacts 39 and into engagement with contacts 44). Contacts 39 and M are sufficiently spaced so that contacts 43 break with contacts 39 prior tomaking with contacts 40. Movement of the armature into its actuated position stresses spring 32 a greater amount than that which exists when the armature is in its normal position so that subsequent de-energization of the electromagnet allows the restoring spring to move the armature and contacts 43 to their normal positions.

The spacings of contacts 39 and 4t and the distance of movement of movable contacts 43 is such as to provide sufficient contact pressure, when the relay is energized, between movable contacts 43 and stationary contacts 4h.

The relay shown in FIG. 6 is identical to that shown in FIGS. l3 except for the shape of the restoring spring and the addition of a stop member and a pressure plate. With reference to FIG. 6, armature 12 is mounted on field member ill by, means including a restoring spring 56 which is indentical to spring 32 except for the fact that the flat end portions are provided with edges 5'7. Because of these edges, spring 56 has the shape of an octagon. 7

Restoring spring 55 is secured to armature 12 by a pair of rivets 5t and a pressure plate 59. Rivets 58 extend through apertures in armature 12, spring 56 and pressure plate 59 and are slightly longer than rivets 34. The end of each rivet on the side of the armature adjacent the restoring spring bears against pressure plate 59.

Pressure plate 59" extends transversely of restoring spring 55 and is transversely bent or curved, as shown in FIG. 8, to provide a pair of parallel edges 60 which abut the restoring spring and hold it, due to the forces created by the rivets, securely against the armature. The width of pressure plate 5? is less than the width of the flat upper end portion of spring as so that edges Gil abut only the flat end portion.

A'stop member 61 is mounted on field member 11 by screws 33. Stop member dll is of non-magnetic material such as brass and has a flat upper portion 63 and a fiat lower portion 62 joined by an inclined medial portion 64 so that portions 62 and d3 lie in parallel planes. Lower portion 62 lies adjacent to and in contact with the flat alt..-

lower portion of spring 56, such lower portions having approximately the same width. The upper portion 63 is spaced from restoring spring 56 a distance great enough so that it does not interfere with normal movement of the armature but close enough so that the restoring spring cannot be moved, due to shock, vibration or jarring, a distance great enough to permanently bend the restoring spring and thereby damage the relay. The thickness of stop member 61, as measured by the distance between the planes in which lie the left surface of portion 63 and the right surface of portion 62, is approximately the same as or slightly less than the thickness of the head of one of screws 33 so that, when installed, the stop member 61 cannot interfere with the operation of adjacent components, such as door 24.

It will be apparent to those skilled in the art that many changes can be made in the details and arrangement of parts without departing from the scope of the invention as defined in the appended claims.

What is claimed is:

1. An electromagnetic relay comprising;

a field member of magnetic material having a generally rectangular base and a generally rectangular leg extending substantially perpendicular to said base a magnetic armature including a first generally rectangular leg which extends sub stantially parallel to said base of said field memher, and

a second generally rectangular leg extending substantially perpendicular to said first leg in a direction toward said base of said field member;

an electromagnet mounted on said base and extending substantially perpendicular thereto in a direction toward said armature,

said rectangular leg of said field member and said second leg of said armature being coplanar and each having a length substantially less than the axial length of said electromagnet so that an edge of said second leg of said armatrue terminates closely adjacent to an edge of aid field member leg,

said edges being in sulficiently close face to face relation so that a magnetic field induced in said field member passes readily into said armature,

a generally flat prestressed leaf type restoring spring comprising:

a generally flat body portion;

an arcuately bent medial portion;

and having at least one opening at each end of said body portion said spring being secured to said field member leg and to said second leg of said armature by enlarged head compression fasteners extending through said openings of said body portion;

an arcuately curved pressure plate between said spring and the enlarged head of one of said compression fasteners, said plate having edges engaging said spring on each side of said compression fastener;

said spring being operable to maintain said edge of said second leg of said armature in closely adjacent relation to said edge of said field member leg, said spring being further operable to pivot said armature away from said electromagnet when said relay is deenergized,

fixed and movable contacts associated with said relay,

and

means connected to said armature to operate said movable contacts in response to movement of said armature.

2. A relay comprising;

a field member including a base,

an electromagnet mounted on said base,

an armature including a fiat body portion extending substantially parallel to said base and being attracta ble by said electromagnet,

said armature further including a leg which extends substantially perpendicular to said body portion of said armature and toward but terminating short of said base,

said field member further including a leg which extends substantially perpendicular to said base in a direction toward said armature,

said legs terminating closely adjacent to one another and lying substantially in the same plane,

a restoring spring of sheet material pivotally mounting said armature on said field member with said terminal edges of said legs closely adjacent to one another,

said restoring spring being connected to each of said armature and said field member legs along the substantially coplanar portions of said legs,

fixed and movable contacts associated with said relay,

and

means connected to said armature to operate said movable contacts in response to movement of said armature;

first stop means engageable with said surface of said flat body portion of said armature remote from said electromagnet to limit the travel of said body portion of said armature away from said electromagnet,

second stop means operable to prevent movement of said armature in a direction parallel to the base of said field member,

said second stop means including a member extending beside said leg of said armature on the side thereof opposite said electromagnet and being operable to prevent permanently distorting said restoring spring beyond its elastic limit.

3. A relay comprising;

a field member including a base,

an electromagnet mounted on said base,

an armature including a flat body portion extending substantially parallel to said base and being attractable by said electromagnet,

said armature further including a leg which extends substantially perpendicular to said body portion of said armature and toward but terminating short of said base,

said field member further including a leg which extends substantially perpendicular to said base in a direction toward aid armature,

said legs terminating closely adjacent to one another and lying substantially in the same plane,

a restoring spring of sheet material pivotally mounting said armature on said field member with said terminal edges of said legs closely adjacent to one another,

said restoring spring being connected to each of said armature and said field member legs along the substantially coplanar portions of said legs,

fixed and movable contacts associated with said relay,

and

means connected to said armature to operate said movable contacts in response to movement of said armature;

first stop means engagable with said surface of said flat body portion of said armature remote from said electromagnet to limit the travel of said body portion of said armature away from said electromagnet,

second stop means operable to prevent movement of said armature in a direction parallel to the base of said field member,

said second stop means including a member extending beside said leg of said armature on the side thereof opposite said electromagnet and being operable to prevent permanently distorting said restoring spring beyond its elastic limit,

said second stop means being in the form of a sheet metal member secured to said field member, and

a portion of said sheet metal member extending generally parallel to and adjacent said restoring spring.

(References on following page) RQEQIEHC'JS Gated by the Examiner UNITED STATES PATENTS Evans 200--87 Callingham 200-87 Doman 200-87 Wertz 20087 Wilson 20087 Fox 200-87 Wilson et a1 317-165 Robinson et a1 20087 Bogue et a1 20087 Martin 20087 7 6 2,917,600 12/59 Smith 200 s7 2,929,001 3/60 Wallace 200-87 3,133,172 5/64 Williams et a1 20087 FOREIGN PATENTS 646,416 6/37 Germany.

847,498 9/60 Great Britain. 1,211,876 3/60 France.

10 BERNARD A. GILHEANY, Primary Examiner.

RICHARD M. WOOD, ROBERT K. SCHAEFER,

Examiners. 

1. AN ELECTROMAGNETIC RELAY COMPRISING; A FIELD MEMBER OF MAGNETIC MATERIAL HAVING A GENERALLY RECTANGULAR BASE AND A GENERALLY RECTANGULAR LEG EXTENDING SUBSTANTIALLY PERPENDICULAR TO SAID BASE A MAGNETIC ARMATURE INCLUDING A FIRST GENERALLY RECTANGULAR LEG WHICH EXTENDS SUBSTANTIALLY PARALLEL TO SAID BASE OF SAID FIELD MEMBER, AND A SECOND GENERALLY RECTANGULAR LEG EXTENDING SUBSTANTIALLY PERPENDICULAR TO SAID FIRST LEG IN A DIRECTION TOWARD SAID BASE OF SAID FIELD MEMBER; AN ELECTROMAGNET MOUNTED ON SAID BASE AND EXTENDING SUBSTANTIALLY PERPENDICULAR THERETO IN A DIRECTION TOWARD SAID ARMATURE, SAID RECTANGULAR LEG OF SAID FIELD MEMBER AND SAID SECOND LEG OF SAID ARMATURE BEING COPLANER AND EACH HAVING A LENGTH SUBSTANTIALLY LESS THAN THE AXIAL LENGTH OF SAID ELECTROMAGNET SO THAT AN EDGE OF SAID SECOND LEG OF SAID ARMATURE TERMINATES CLOSELY ADJACENT TO AND EDGE OF SAID FIELD MEMBER LEG, SAID EDGES BEING IN SUFFICIENTLY CLOSE FACE TO FACE RELATION SO THAT A MAGNETIC FIELD INDUCED IN SAID FIELD MEMBER PASSES READILY INTO SAID ARMATURE, A GENERALLY FLAT PRESTRESSED LEAF TYPE RESTORING SPRING COMPRISING: A GENERALLY FLAT BODY PORTION; AN ARCUATELY BENT MEDIAL PORTION; AND HAVING AT LEAST ONE OPENING AT EACH END OF SAID BODY PORTION SAID SPRING BEING SECURED TO SAID FIELD MEMBER LEG AND TO SAID SECOND LEG OF SAID ARMATURE BY ENLARGED HEAD COMPRESSION FASTENERS EXTENDING THROUGH SAID OPENINGS OF SAID BODY PORTION; AN ARCUATELY CURVED PRESSURE PLATE BETWEEN SAID SPRING AND THE ENLARGED HEAD OF ONE OF SAID COMPRESSION FASTENERS, SAID PLATE HAVING EDGES ENGAGING SAID SPRING ON EACH SIDE OF SAID COMPRESSION FASTENER; SAID SPRING BEING OPERABLE TO MAINTAIN SAID EDGE OF SAID SECOND LEG OF SAID ARMATURE IN CLOSELY ADJACENT RELATION TO SAID EDGE OF SAID FIELD MEMBER LEG, SAID SPRING BEING FURTHER OPERABLE TO PIVOT SAID ARMATURE AWAY FROM SAID ELECTROMAGNET WHEN SAID RELAY IS DEENERGIZED, FIXED AND MOVABLE CONTACTS ASSOCIATED WITH SAID RELAY, AND MEANS CONNECTED TO SAID ARMATURE TO OPERATE SAID MOVABLE CONTACTS IN RESPONSIVE TO MOVEMENT OF SAID ARMATURE. 